com.openinventor.inventor.devices

Class SoBufferObject

java.lang.Object

com.openinventor.inventor.Inventor

com.openinventor.inventor.devices.SoBufferObject

All Implemented Interfaces:

SafeDisposable

Direct Known Subclasses:

SoCpuBufferObject, SoGpuBufferObject, SoInteropBufferObject

public abstract class SoBufferObject
extends Inventor
implements SafeDisposable

Abstract base class for buffer object management. This class provides generic functions to manage buffer objects.

There are specific implementations of this class for buffer objects on each type of device:

• SoCpuBufferObject: A buffer in CPU system memory.
• SoGLBufferObject: A buffer in GPU memory managed through the OpenGL API.

In many cases the abstract SoBufferObject methods allow the application to handle buffer objects without knowing the specific type of the buffer. This is very convenient when computation is implemented on multiple devices.

Since version 8.0, some Open Inventor classes take or return data using an SoBufferObject (or derived class). For example texture images (see SoSFImage), geometry data (see SoBufferedShape) and tiles of volume data (see SoLDMDataAccess).

Creating a buffer object

Before creating a non-CPU buffer object you must bind (then unbind) a valid context for the target device. For example, to create an OpenGL buffer object SoGLBufferObject) you can bind the viewer's context using methods in the view class or you can use the class SoGLContext. See the example on the SoGLBuffer page. For an existing buffer object you can use the buffer's bind()/unbind() methods or get a valid context to bind using thegetContext() method. Binding this context is necessary before changing buffer properties or calling setSize(), memcpy(), memset(), etc.

Allocating memory in a buffer object:

Use the setSize() method to allocate memory in a buffer object. (Note that you must bind a valid context before calling this method on non-CPU buffer objects.) Generally buffer objects have zero size when created. However some buffer object classes have a constructor that takes an existing block of memory as a parameter. In that case the initial size is non-zero. You must allocate memory before copying data into a buffer object using either the memcpy() method or a direct reference . Memory is automatically allocated, if necessary, when a buffer object is mapped into another buffer object.

Loading data and retrieving data:

• Some buffer objects, e.g. SoCpuBufferObject, have a constructor that takes an existing block of memory as a parameter. In this case the buffer object is automatically set to the necessary size to contain the specified data. Creating an SoCpuBufferObect that "wraps" the existing data is usually the first step in loading data into a non-CPU buffer using memcpy() or map().
• The memcpy() methods copy data into a buffer object from another buffer object. For example to copy data into an OpenGL buffer from a CPU buffer. Before using these methods on a non-CPU buffer object, you must bind (then unbind) a valid context for the target device. The buffer object must be large enough (have enough memory allocated) to hold the data. See the allocating memory topic above.
• The memset() methods fill a buffer object with a specified value. Before using these methods on a non-CPU buffer object, you must bind (then unbind) a valid context for the target device. The buffer object must be large enough (have enough memory allocated) to hold the data. See the allocating memory topic above.
• The map() methods that have a buffer object parameter "map" one buffer object into another, usually to allow the data to be accessed on a different device. When the access mode is READ_ONLY or READ_WRITE, the contents of the source buffer are available through the target buffer object after the map() call. If necessary, Open Inventor will automatically do an inter-device transfer of the data. When the access mode is SET or READ_WRITE, the contents of the modified target buffer object are available through the source buffer object after the unmap() call. If necessary, Open Inventor will automatically do an inter-device data transfer.
• Some buffer object classes provide a map() method that maps the buffer's data into CPU memory and returns a reference. If necessary, Open Inventor will automatically do an inter-device transfer of the data. While the buffer is mapped the application can directly modify its data using the returned reference. If the access mode is SET or READ_WRITE, the modified data will be available through the buffer object after the unmap() call. If necessary, Open Inventor will automatically do an inter-device data transfer.

See also:

SoCpuBufferObject, SoGLBufferObject, SoCpuDevice, SoGLDevice, SoBufferedShape

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SoBufferObject.AccessModes This enum provides the possible access modes for a mapped buffer object.

Nested classes/interfaces inherited from class com.openinventor.inventor.Inventor

Inventor.ConstructorCommand

Field Summary

Fields

Modifier and Type	Field and Description
static long	SO_BUFFER_SIZE_ALL Used to indicate that we want to use the whole buffer.

Fields inherited from class com.openinventor.inventor.Inventor

VERBOSE_LEVEL, ZeroHandle

Method Summary

Modifier and Type	Method and Description
void	clearInstance() Free the memory allocated by the buffer object.
SoBufferObject	createInstance() Create a new buffer with the same properties as the current one.
boolean	dispose() Explicitly call this method to force object to dispose its unmanaged resources.
static SoCpuBufferObjectCache	getBufferObjectCache() Returns the cache manager object.
SoDeviceContext	getContext() Returns the device context where this buffer is valid.
SoBufferObject	getMappedBufferObject() Returns a pointer to the buffer object which is mapped by the actual object.
SoBufferObject.AccessModes	getMappedBufferObjectAccessMode() Returns the access mode used for the buffer mapping.
long	getMappedBufferObjectPosition() Returns the position in the source buffer mapped in this buffer.
long	getMappedBufferObjectSize() Returns the size of the mapped area in bytes.
long	getSize() Returns the size, in bytes, of the buffer object.
boolean	isDisposable() Returns a boolean flag which indicates if it is safe to call SafeDisposable.dispose() on the object.
void	lockBuffer() Locks the buffer against concurrent calls from different threads.
java.nio.ByteBuffer	map(SoBufferObject.AccessModes accessMode) Calls map(accessMode, (long)0, (long)SO_BUFFER_SIZE_ALL).
java.nio.ByteBuffer	map(SoBufferObject.AccessModes accessMode, long offset) Calls map(accessMode, offset, (long)SO_BUFFER_SIZE_ALL).
java.nio.ByteBuffer	map(SoBufferObject.AccessModes accessMode, long offset, long count) Map the buffer to a system memory address and allows the mapping of a sub part of the buffer object into CPU memory.
void	map(SoBufferObject targetBufferObject, SoBufferObject.AccessModes accessMode) Calls map(targetBufferObject, accessMode, (long)0, (long)SO_BUFFER_SIZE_ALL).
void	map(SoBufferObject targetBufferObject, SoBufferObject.AccessModes accessMode, long startPosition) Calls map(targetBufferObject, accessMode, startPosition, (long)SO_BUFFER_SIZE_ALL).
void	map(SoBufferObject targetBufferObject, SoBufferObject.AccessModes accessMode, long startPosition, long mappingSize) Maps the current buffer object into the specified buffer object.
void	memcpy(SoBufferObject sourceBufferObject) Calls memcpy(sourceBufferObject, (long)0, (long)0, (long)SO_BUFFER_SIZE_ALL).
void	memcpy(SoBufferObject sourceBufferObject, long destOffset) Calls memcpy(sourceBufferObject, destOffset, (long)0, (long)SO_BUFFER_SIZE_ALL).
void	memcpy(SoBufferObject sourceBufferObject, long destOffset, long sourceOffset) Calls memcpy(sourceBufferObject, destOffset, sourceOffset, (long)SO_BUFFER_SIZE_ALL).
void	memcpy(SoBufferObject sourceBufferObject, long destOffset, long sourceOffset, long copySize) Copies data from the specified buffer object into this buffer object.
boolean	setSize(long size) Sets the size in bytes of the buffer object.
void	unlockBuffer() Unlocks the buffer object.
void	unmap() Unmaps the buffer from CPU address space.
void	unmap(SoBufferObject bufferObject) Unmap this buffer from the specified buffer object.

Methods inherited from class com.openinventor.inventor.Inventor

getNativeResourceHandle

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

SO_BUFFER_SIZE_ALL

public static final long SO_BUFFER_SIZE_ALL

Used to indicate that we want to use the whole buffer.

See Also:

Constant Field Values

Method Detail

map

public java.nio.ByteBuffer map(SoBufferObject.AccessModes accessMode,
                               long offset)

Calls map(accessMode, offset, (long)SO_BUFFER_SIZE_ALL).

map

public void map(SoBufferObject targetBufferObject,
                SoBufferObject.AccessModes accessMode)

Calls map(targetBufferObject, accessMode, (long)0, (long)SO_BUFFER_SIZE_ALL).

dispose

public boolean dispose()

Description copied from class: Inventor

Explicitly call this method to force object to dispose its unmanaged resources. The object may not be reused in the application code after this call.

Specified by:

dispose in interface SafeDisposable

Overrides:

dispose in class Inventor

Returns:

true if this object native resources were successfully disposed; false if it was already disposed or no native resources has been registered for this object.

map

public java.nio.ByteBuffer map(SoBufferObject.AccessModes accessMode)

Calls map(accessMode, (long)0, (long)SO_BUFFER_SIZE_ALL).

map

public void map(SoBufferObject targetBufferObject,
                SoBufferObject.AccessModes accessMode,
                long startPosition)

Calls map(targetBufferObject, accessMode, startPosition, (long)SO_BUFFER_SIZE_ALL).

memcpy

public void memcpy(SoBufferObject sourceBufferObject,
                   long destOffset,
                   long sourceOffset)

Calls memcpy(sourceBufferObject, destOffset, sourceOffset, (long)SO_BUFFER_SIZE_ALL).

isDisposable

public boolean isDisposable()

Description copied from interface: SafeDisposable

Returns a boolean flag which indicates if it is safe to call SafeDisposable.dispose() on the object.

Specified by:

isDisposable in interface SafeDisposable

Returns:

true if the object can be disposed in a safe manner

memcpy

public void memcpy(SoBufferObject sourceBufferObject)

Calls memcpy(sourceBufferObject, (long)0, (long)0, (long)SO_BUFFER_SIZE_ALL).

memcpy

public void memcpy(SoBufferObject sourceBufferObject,
                   long destOffset)

Calls memcpy(sourceBufferObject, destOffset, (long)0, (long)SO_BUFFER_SIZE_ALL).

map

public java.nio.ByteBuffer map(SoBufferObject.AccessModes accessMode,
                               long offset,
                               long count)

Map the buffer to a system memory address and allows the mapping of a sub part of the buffer object into CPU memory. Notes:

• The unmap() method must be called before using the buffer.

Returns:

Reference to data in the mapped region of the buffer memory.

unmap

public void unmap()

Unmaps the buffer from CPU address space.

map

public void map(SoBufferObject targetBufferObject,
                SoBufferObject.AccessModes accessMode,
                long startPosition,
                long mappingSize)

Maps the current buffer object into the specified buffer object.
This is useful in order to use a buffer in multiple contexts. The default is to map the entire contents of this buffer, but it is also possible to map a subset of this buffer's memory using the startPosition and mappingSize parameters.

A source buffer may be mapped into multiple target buffers. However a target buffer can only be mapped from one source buffer at a time. If a different source buffer is currently mapped into the target buffer, it is automatically unmapped and may be left in an undefined state.

Note: If the current buffer is empty or startPosition is beyond the end of the managed memory, the buffer is not mapped (and an error message is issued in debug builds).

Parameters:

targetBufferObject - The buffer object which will be the mapped version of this buffer.

accessMode - The access mode used for the mapping.

startPosition - Offset (in bytes) in source buffer to map from (default is start of buffer).

mappingSize - Size (in bytes) from the startPosition, if SO_BUFFER_SIZE_ALL then the whole buffer is mapped.

getSize

public long getSize()

Returns the size, in bytes, of the buffer object.

Returns:

The size in bytes of the buffer object.

lockBuffer

public void lockBuffer()

Locks the buffer against concurrent calls from different threads.
This is a blocking call. In other words it will not return immediately if another thread currently has the buffer locked.

getBufferObjectCache

public static SoCpuBufferObjectCache getBufferObjectCache()

Returns the cache manager object. This object manages a cache of SoCpuBufferObject objects. SoBufferObject creates an instance of this class that is primarily used for the LDM tile cache (see SoLDMGlobalResourceParameters for more information). The buffer object cache can be accessed using the SoBufferObject static method getBufferObjectCache. Default size is 50 or the value of OIV_BUFFER_OBJECT_CACHE_SIZE.

setSize

public boolean setSize(long size)

Sets the size in bytes of the buffer object.

If the requested size is the same as the current size, this method does nothing and returns true. If there is existing memory that is owned by the buffer object, that memory is released. If the requested size is zero, the buffer object is now empty.

Parameters:

size - The requested size in bytes.

Returns:

true if the operation was successful.

unlockBuffer

public void unlockBuffer()

Unlocks the buffer object.
If a thread calls lockBuffer() then it must call unlockBuffer() to allow other threads to lock the buffer.

unmap

public void unmap(SoBufferObject bufferObject)

Unmap this buffer from the specified buffer object.
In other words, remove the specified target buffer from the list of buffers which this buffer is mapped to. If the access mode supports writing, the specified buffer is sync'd with the current buffer. An error is reported (in debug builds) if the buffer is not mapped to the specified buffer

Parameters:

bufferObject - Buffer to be unmapped.

getMappedBufferObjectAccessMode

public SoBufferObject.AccessModes getMappedBufferObjectAccessMode()

Returns the access mode used for the buffer mapping.

getMappedBufferObject

public SoBufferObject getMappedBufferObject()

Returns a pointer to the buffer object which is mapped by the actual object.

getMappedBufferObjectSize

public long getMappedBufferObjectSize()

Returns the size of the mapped area in bytes.

Returns:

The size of the mapped area.

getMappedBufferObjectPosition

public long getMappedBufferObjectPosition()

Returns the position in the source buffer mapped in this buffer.

Returns:

Returns a position in bytes.

createInstance

public SoBufferObject createInstance()

Create a new buffer with the same properties as the current one.
The new instance will have the same context or device properties, but no memory is allocated.

memcpy

public void memcpy(SoBufferObject sourceBufferObject,
                   long destOffset,
                   long sourceOffset,
                   long copySize)

Copies data from the specified buffer object into this buffer object.
If the size or the offset are not valid an error is reported (SoDebugError). This buffer is not resized, if it is too small an error is reported.

Warning Source and destination overlaping support is implementation dependent, if not supported an error is reported.

Parameters:

sourceBufferObject - The buffer object to be copied.

destOffset - The starting offset in the destination buffer object, useful for data subsets.

sourceOffset - The starting offset in the source buffer object, useful for data subsets.

copySize - The number of bytes to copy from the source buffer object (SO_BUFFER_SIZE_ALL means all).

getContext

public SoDeviceContext getContext()

Returns the device context where this buffer is valid.

Returns:

A device context.

clearInstance

public void clearInstance()

Free the memory allocated by the buffer object.